In other words, where did he look up to?
Isaac Newton, being arguably the most famous physicist aside from Einstein, is an obvious choice for scientists respected by Einstein. I will not elaborate on Newton here, as I think there is a more interesting choice. Here is an article detailing the profound respect Einstein had for Newton:
http://www.pbs.org/wgbh/nova/physics/einstein-on-newton.html
One scientist Einstein greatly admired was James Clerk Maxwell. Maxwell was the physicist who discovered the laws governing electromagnetism (look up 'Maxwell Equations' for a set of four equations which completely describe classical electromagnetic phenomena).
This discovery was the catalyst the led to the proposition that the speed of light was the same in all inertial frames of reference. Subsequently, this led to the discovery of special relativity, one of Einstein's first great publications.
Einstein described Maxwell's work as the "most profound and the most fruitful that physics has experienced since the time of Newton".